A High-Performance Algorithm to Calculate Spin- and Parity-Dependent Nuclear Level Densities

TL;DR

This paper introduces a high-performance, parallelized algorithm for calculating spin- and parity-dependent nuclear level densities using the moments method, enabling analysis of larger model spaces and estimation of ground state energies.

Contribution

The paper presents a novel, parallelized algorithm and code for shell model nuclear level densities, allowing calculations in larger model spaces and estimation of ground state energies.

Findings

Successfully tested on up to 4000 cores.

Estimated ground state energies for 64Ge and 68Se.

Demonstrated calculation of level densities in extended model spaces.

Abstract

A new algorithm for calculating the spin- and parity-dependent shell model nuclear level densities using the moments method in the proton-neutron formalism is presented. A new, parallelized code based on this algorithm was developed and tested using up to 4000 cores for a set of nuclei from the sd-, pf-, and pf + g9/2 - model spaces. By comparing the nuclear level densities at low excitation energy for a given nucleus calculated in two model spaces, such as pf and pf + g9/2, one could estimate the ground state energy in the larger model space, which is not accessible to direct shell model calculations due to the unmanageable dimension. Examples for the ground state energies of for 64Ge and 68Se in the pf + g9/2 model space are presented.